Include MediaItem duration auto update as default for playlist example

[pablodemergelina]

Documentation request for the following page(s)

audio_service/audio_service/example/lib/example_playlist.dart

Line 475 in f94d0d3

Rx.combineLatest4<int?, List<MediaItem>, bool, List<int>?, MediaItem?>(

Section(s) in question

// Broadcast media item changes.
Rx.combineLatest4<int?, List<MediaItem>, bool, List<int>?, MediaItem?>(
    _player.currentIndexStream,
    queue,
    _player.shuffleModeEnabledStream,
    _player.shuffleIndicesStream,
    (index, queue, shuffleModeEnabled, shuffleIndices) {
  final queueIndex =
      getQueueIndex(index, shuffleModeEnabled, shuffleIndices);
  return (queueIndex != null && queueIndex < queue.length)
      ? queue[queueIndex]
      : null;
}).whereType<MediaItem>().distinct().listen(mediaItem.add);

Suggested improvement

Really usefull Stackoverflow answer https://stackoverflow.com/questions/69346791/how-to-get-the-audio-file-url-total-duration-using-audio-service-package by Sho in order to get MediaItems duration automatically when loading audio. This can be included as default on example_playlist or a least a comment explaining or referencing Stackoverflow answer.

// Broadcast media item changes.
Rx.combineLatest5<int?, List<MediaItem>, bool, List<int>?, Duration?, MediaItem?>( // <- add duration
    _player.currentIndexStream,
    queue,
    _player.shuffleModeEnabledStream,
    _player.shuffleIndicesStream,
    _player.durationStream, // <- add listening to durationStream here
    (index, queue, shuffleModeEnabled, shuffleIndices, duration) {
  final queueIndex =
      getQueueIndex(index, shuffleModeEnabled, shuffleIndices);
  return (queueIndex != null && queueIndex < queue.length)
      ? queue[queueIndex].copyWith(duration: duration) // <- sink mediaItem provided with duration
      : null;
}).whereType<MediaItem>().distinct().listen(mediaItem.add);

[muhammadkamel]

Please, note that the distinct method, prevent updating the duration for the selected item.